1. Field of the Invention
The invention relates to systems for communicating with peripheral devices and controllers, and more particularly, to systems for wireless communications with such devices.
2. Description of Background Art
As the use of personal computers has been more ubiquitous in all phases of professional and personal life, and with the increasing popularity of graphical user interfaces for both personal computers and workstations, the need for sophisticated methods of communication between a peripheral and a host system has become fundamental to the successful operation of the overall system. The variety of available peripherals has expanded dramatically with the increasing power available from the microprocessors available for such systems, but peripherals such as keyboards, mice, trackballs, touch pads, game pads, joysticks, remote controllers, and so on are well-known for use with host systems of many types, including PC's, workstations and other types of microprocessor-controlled devices including video game systems, or other office or household devices. To operate in conventional environments, each of these peripherals is connected to its host system via a hardware port. Moreover, peripherals in conventional environments communicate with a host through a proprietary protocol.
While such communications protocols between conventional host systems and peripherals have been very successful at bringing substantial power and flexibility to the user, they do suffer from some limitations. Among others, most host systems have only a limited number of available ports, and cannot share such ports for simultaneous operation with a number of peripherals. This imposes significant limitations on the flexibility with which the system can be used. For example, if only two serial ports are available, only two serial peripherals can be simultaneously connected to the host system. Similarly, and particularly applicable to interactive devices such as modem video games or teaching environments, it has been difficult to permit multiples of players to communicate with a host system in a simultaneous manner without providing a separate communications channel for each such device.
Devices that communicate with their host systems without hard-wired connections are also well known in the art. Infrared remote control devices for use with modern home electronics such as television, VCR or stereo are readily available in the marketplace. However, such devices have little computational power, and basically use relatively simple protocols to communicate to a host which of several buttons have been depressed by the user of the remote device. In conventional computing environments, systems such as the IBM PC Jr. implemented a wireless keyboard using infrared techniques, but suffered because the infrared link needed to be pointed almost precisely at the associated receiver on the host to maintain communications. This proved to be difficult to achieve, leading to abandonment of the design and the system. In general, infrared devices can operate only if they are pointed in the direction of the receiver, which is usually at or near the host system.
More recently, other wireless devices have been introduced. For example, the Microsoft Cordless Mouse and the Genius NewScroll Wireless Mouse each use an RF communications link. In addition, various other infrared and RF devices by various other manufacturers are known in the art. However, while these devices have been very effective at providing communication between a single peripheral and an associated host, they have not provided the broader solution necessary to connect multiple types of devices to the host, nor have they permitted concurrent connection of multiple devices to the host.
A new type of external bus that is expected to replace parallel and serial ports is the universal serial bus (USB). Introduced in computers shipped in 1997, USB has a transfer speed of up to 12 megabits per second (Mbps). It is designated primarily for low-to-mid-speed peripheral devices, such as keyboards, mice, modems, printers, joysticks, and some scanners. A main advantage of USB over traditional ports is that it offers easy expandability (e.g., up to 127 devices can be daisy chained). All USB devices support plug and play and hot swapping as well. The computer automatically recognizes any USB device as soon as it's plugged in or added to the chain. Desktop computers that support USB typically have two four-pin USB ports—one for a keyboard and mouse daisy chain, the other to daisy chain all other USB devices.
The advantages of USB make it ideally suited for use in a wireless system, particularly for concurrent connection of multiple devices to the host computer. Thus, by integrating the USB into a wireless system, an increased number of configurations are possible.
Accordingly, there is a need for a system capable of permitting multiple peripheral devices to communicate with a host system in a simultaneous manner. Such a method and apparatus should include one or more USB ports to maximize expandability and simplify the connection of peripherals to the host computer.